Abstract
Introduction: The accuracy of implantation is an accepted prognostic factor for the long term survival of a unicompartmental knee prosthesis (UKP). Minimal invasive technique is recommended for faster post-operative recovery. We developed an adaptation of a non image based system for either conventional or minimal invasive UKP implantation. We hypothesized that the used non image based navigation system will allow to place a UKP in the same position for both conventional and minimal-invasive approach.
Methods: 20 patients were operated on with this experimental minimal invasive navigated technique (group A) and compared to a group of 20 cases operated with the conventional navigated technique (group B), matched to the study group according to age, gender andseverity of the coronal deformation. Coronal mechanical femorotibial angle and coronal and sagittal orientation of the components were measured on post-operative antero-posterior and lateral long leg X-rays. The rate of satisfactory implanted prostheses was compared in both groups with a Chi-square test with a 0.05 limit of significance.
There was no significant difference in the pre-operative data between both groups. The post-operative coronal group A and 17 cases in group B. The prosthesis was optimally implanted in 17 cases in group A and 18 cases in group B. No difference was statistically significant.
Discussion-Conclusion: The used navigation system allowed a very precise implantation of a UKP for both conventional and minimal invasive navigated technique.
Correspondence should be addressed to Richard Komistek, PhD, International Society for Technology in Arthroplasty, PO Box 6564, Auburn, CA 95604, USA. E-mail: ista@pacbell.net
